A base station is divided into two parts: a radio equipment controller (REC) and a radio equipment (RE). The REC and the RE are generally connected in a cascaded manner by using an optical communications line. In this manner, once a fault occurs at any point in the communications line, the REC cannot communicate with any RE after the fault point, and manual onsite processing is required, which brings about a high onsite maintenance cost, increases a service interruption time, and affects user experience.